Container and method of forming same



April 5, 1966 c. w. HEINLE CONTAINER AND METHOD OF FORMING SAME 2 Sheets-Sheet 1 Filed June 11 1963 Zap.

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April 5, 1966 c. w. HEINLE 3,244,131

CONTAINER AND METHOD OF FORMING SAME Filed June 11 1963 2 Sheets-Sheet 2 IN VENTOR.

gm: flgdj United States Patent 3,244,131 CONTAINER AND METHOD OF FORMING SAME Carl William Heinle, Short Hills, N.J., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed June 11, 1963, Ser. No. 287,011 Claims. (Cl. 113-121) The present invention relates to improvement in easy.- opening containers of the type wherein a single score line is formed in the cover skirt in order to provide a tearing strip which may be torn away manually to eliminate the locking connection between the cover and the container body and thereby permit easy removal of the cover.

Containers of this general type have been long known in the art, but have never attained very great popularity owing to the fact that the container materials used have not been easily tearable. With the recent trend toward the use of aluminum and lightweight tinplate in containers, however, interest in this general type of container has been revived, because a container cover made of aluminum or lightweight tinplate may easily be torn along the score line manually without requiring the use of a key or other opening device. In the usual version of this container, the tearing strip is formed in the cover skirt prior to the time the skirt is crimped or pressed onto the container body, and the upper portion of the container body is provided with an out wardly and downwardly turned open hem or curl beneath which the cover skirt is crimped. While this version of the container has proved generally satisfactory, there is a tendency for the preformed score line in the cover skirt to crack during the seaming operation, and for the outer raw edge of the hem to cause shearing of the cover skirt when it is pressed thereagainst during the seaming operation. i

The present invention contemplates a method of overcoming these problems by forming the score line in the cover skirt simultaneously with the seaming operation, and by providing the upper portion of the container body with a flattened hem wherein the raw body edge is concealed so that the raw edge will not be in contact with the cover skirt during the seaming operation. As an addition- =al feature, the invention contemplates a seaming operation wherein this flattened closed hem is formed from a hollow curl which is reshaped in such manner that the upper portion of the curl is left substantially unflattened so as to provide an outwardly extending hollow curl over which the cover skirt may be snapped to firmly retain the cover on the container body when it is used as a reclosure.

An object of the present invention, therefore, is the provision of an improved method of forming an easy open tear strip container.

Another object is to provide a method of forming a scored tear strip in the depending skirt of a cover simultaneously with the seaming operation in a manner to avoid any damage to the cover skirt or container body.

A further object is the provision of such a method wherein the cover skirt and container body are so formed .as to provide a snap action between the skirt and the upper, unflattened portion of the body curl of the container body, thereby enabling the cover to be used as a reclosure.

A still further object is to provide a container formed by utilization of the instant method.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings: FIGURE 1 is a side elevational view of an easy open- 3,244,131 Patented Apr. 5, 1966 ing container formed according to the method of the present invention;

FIG. 2 is a fragmentary, enlarged sectional viewtaken substantially along line 22 of FIG. 1;

FIG. 3 is a partial side elevational view of the con.- tainer illustrated in FIG. 1, showing the tearing strip partially removed from the cover skirt;

FIG. 4 is a view similar to FIG. 3, showing the cover skirt after the tearing strip has been completely removed therefrom;

FIG. 5 is a fragmentary, enlarged sectional view taken substantially along line 55 in FIG. 4;

FIG. 6 is a fragmentary, enlarged elevational view in section of the upper portion of the container of FIG. 1, showing the peripheral body and cover portions as they appear prior to the seaming operation;

FIG. 7 is a view similar to FIG. 6, showing the peripheral body and cover portions as they appear after the completion of the first seaming operation, the view also illustrating in section a portion of the seaming roll and chuck which cooperate to perform this step of the instant method; and

FIG. 8 is a view similar to FIG. 7 of the upper portion of the container after the completion of the second seaming and simultaneous scoring operation, showing in section a portion of the combined seaming and scoring rolls and the seaming chuck utilized to perform this step of the instant method.

As a preferred or exemplary embodiment of the present invention, FIG. 1 discloses an easy opening container which has been formed by the method of the instant in vention. The container comprises a cylindrical tubular body 10 which is preferably a one-piece drawn shell of metal, such as aluminum or tinplate, or other suitable material. It is noted, however, that the body 10 need not be of one-piece construction, but instead may be provided with abottom end closure and/or a side seam. The upper open end of the body is closed by a cover 12 which preferably is formed of an easily tearable metal, such as aluminum, or of other suitable materials such as tinplate or the like.

As shown in FIG. 2, the upper end of the body wall 14 is initiallyturned outwardly to form a hollow curl 16 having an outer, inwardly inclined wall 18 which terminates in a flattened, U-shaped hem 20 which engages the body wall 14. The raw edge 24 of the body wall 14 isdisposed at the upper end of the inner leg 25 of the flattened U-shaped hem 20 between the main body wall 14 and the outer leg 26 of the U-shaped hem 20. i

The cover 12 is provided with a depressed countersink panel 28 which at its outer edge is bent outwardly and upwardly to form a countersink wall 30. At its upper end, the countersink wall 30 is sharply bent outwardly to form a flat upper surface 32 and then downwardly to form a depending cover skirt or flange 34. The cover skirt 34 comprises an upper vertical portion 36 which merges into an inwardly inclined portion 38 that is pressed against the inwardly extending wall 18 of the hollow curl 16. The inclined portion 38 merges with a lower depending skirt portion 40 which is pressed against the flattened hem 20, the lowermost portion 39 of the skirt portion 40 being offset inwardly beneath the lower end of the hem 20 into engagement with the main body wall 14. In order to more firmly secure the cover 12 to the upper end of the container body, the cover skirt 34 and body wall 14 are provided with interfitting grooves or indentations 42 and 44, respectively, which are formed in a manner to be described hereinafter. If a hermetic seam is desired in the sealed container, the upper, interior surface of the cover 12 is lined with a suitable resilient lining compound 45, which may have a latex base.

A circumferential score line 46 is formed in the depending skirt portion 40 to define an easily removable tearing strip 48 therein. As shown in FIGS. 1 and 3, the tearing strip 48 .is provided with a depending .tearing tongue 50 which may "be grasped between the thumb and forefinger of the consumer. When removal of the cover 12 is desired, the tongue 50 .is grasped and pulled or twisted diagonally upwardly (to the right as seen in FIGS. 1 and 3). This twisting action results in a tear 52 (see FIG. 3) which extends across the tearing strip 48 to the score line 46. Thereafter, the tongue 50 is pulled circumferentially around the container (see FIG. 3) to detach the tearing strip 48 from the cover 12 along the score line 46 and .to dest i y the locking connection between the cover 12' and the body wall 14.

FIGS, 4 and 5 illustrate the cover 12 and container body after the tearing strip 48 is completely removed from the cover skirt 34. The cover is retained on the container body'by the inwardly inclined portion 38 of the cover skirt .34, which portion is in engagement with the downwardly and inwardly inclined wall 18 of the hollow curl 16. In order to remove the cover 12 from the container body 10, the cover is manually lifted therefrom against the force .of the inwardly inclined skirt portion 38. This causes the skirt portion 38 to flex outwardly ,(to the right as seen in FIG. 5) toa suificient degree to allow the cove-r to be completely removed from the container body. After such removal, the inherent resiliency of the skirt portion 38 returns it to its original position, as shown in broken lines in FIG. 5. This cooperation between the resilient portion 38 of the cover skirt 34 and the wall 18 of the curl 16 is particularly advantageous in that it provides a snap action between the cover skirt and the container body, with the result that the cover 12 may be conveniently used as a secure reclosure for the container. When the cover 12 is snapped over the curl 16 for use as a reclosure, the resilient skirt .portion 38 again engages the curl wall 18 to firmly retain the cover 12 on the container body 10.

In performing the method steps of the instant invention, the upper portion of the body wall 14 is initially provided with a hollow, outwardly extending closed curl 53 which is substantially circular in cross section, the raw edge 24 thereof being disposed within the confines of the curl, as shown in FIG. 6. The cover 12, comprising the depending annular skirt 34 and having the lining compound 45 in the ,upper, interior portion thereof,

is then positioned on the container body 10, with the cover skirt 34 extending downwardly ,over and beyond the curl 53.

Thereafter, asseen in FIG. 7, a seaming chuck C is inserted into the cover 12 and fits snugly against the depressed countersink panel 28 and wall 30 of the cover. The chuck C is provided with a laterally outwardly extending portion 54 which engages the fiat upper surface 32 of the cover 12 and presses the cover 12 and body 10 firmly together. After the seaming chuck C has been so positioned, the cover skirt 34 is rolled laterally inwardly in a first rolling operation by a circular first seaming roll R which is pressed against the skirt 34 in any suitable manner and rolled completely therearound. As a result of the inward pressure exerted by the seaming roll R the cover skirt 34 is pressed against the curl 53 and the latter is partially collapsed into engagement with the upper portion of the body wall 14. The first operation seaming roll R includes an annular projection or step 56 which forms the inwardly inclined portion 38 and the depending portion 40 of the cover skirt 34, and reforms the curl 53 to form its upper portion into the curl 16 and its lower portion into the hem 20. The roll R also includes a second step 57 which crimps the skirt portion 39 beneath the hem 20. The lining compound 45, which is carried by the upper, interior portion of w the cover 12, is compressed between the cover 12 and the curl 16 to form a hermetic sea]. This first rolling operation forms the seam between the cover 12 and container body 10 to within approximately ,010 to .015 inch of its final tightness.

After the first rolling operation is completed, the seam between the cover 12 and container body 10 is rolled to its final or desired tightness in a second operation wherein a second seaming roll R (see FIG. 8) is pressed against the skirt 34 by any suitable pressure means (not shown). The roll R is provided with an annular bead or projection 58 in a lower portion 60 thereof which serves to form the interlocking grooves or indentations 42 and 44 in the cover skirt portion 39 and body wall -14, respectively. The locking action of these indentations 42 and 44 serves .to more firmly secure the cover 12 to the upper end of the container body 10.

Simultaneously with this second rolling operation, the circumferential score line 46 is rolled into the cover skirt 34 by a circular scoring roll 62 to form the tearing strip 48 in the cover skirt 34. As shown in FIG. 8, the scoring roll 62 is disposed between an upper portion 64 and the lower portion 60 of theseaming roll R Preferably, the scoring roll 62 and the portions 60 and 64 are separate pieces which are secured together in any suitable manner. .An oblique cutting surface 66 is provided on the scoring roll 62 and projects outwardly beyond the adjacent portions .of the seaming roll R a predetermined distance which is less than the thickness of the cover skirt 34. The lower portion of the cutting surface 66 is at a sharp angle to the bottom portion of the scoring roll 62 to insure that, when the tearing tongue 50 is pulled diagonally upwardly to the score line 46, there will be no tendency for the line of tear to thereafter tear out of the score line 46 and downwardly across the tearing strip 48 to prevent easy opening of the container, should the tongue .50 be pulled in a downward direction. An oblique shaping surface 68 is provided on the scoring roll just above the cutting surface 66 and serves to flatten the inwardly inclined portion 38 of the cover skirt 34 during the scoring operation.

The scoring roll penetration into the cover skirt 34 is controlled by the predetermined distance by which the scoring roll 62 projects outwardly beyond the adjacent portion 60 of the seaming roll R and also by the upper, laterally extending portion 54 of the chuck C which engages the upper portion 64 of the seaming roll R (see FIG. 8). This engagement between the seaming roll .portion 64 and upper portion 54 of the chuck C further serves to control the thickness of the seam between the cover 12 and the container body 10. It is noted that the raw edge 24 of the body wall 14 is disposed at the upper end of the inner wall 25 of the flattened, U-shaped hem 20, which end is located above the score line 46 in the cover skirt 34. Thus, when the scoring roll 62 penetrates the cover skirt, the flattened, U-shaped hem 20 serves as an anvil to prevent any shearing of the cover skirt 34 or body wall 14 during the scoring operation.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. The method of forming an easy opening container, comprising the steps of positioning a cover in the open end of a container body having an outwardly turned closed curl on the marginal portion thereof adjacent said open end, said cover having a peripheral skirt extending over said marginal portion, pressing said cover skirt into contact with said closed curl and said marginal body portion to seam said cover and said container body together and to reform into a flattened hem only a portion of said closed curl spaced from said open end to 55 thereby provide a substantially unflattened portion of said curl at said open end, and forming a circumferential score line in the outer surface of said cover skirt to create a removable tearing strip therein, whereby said cover may be easily released from said container body by removal of said tearing strip.

2. The method of claim 1 wherein said score line is formed in said cover skirt adjacent to said flattened hem and between the extremities thereof.

3. The method of claim 2 wherein the raw edge of said container body is positioned at the extremity of said flattened hem nearest the'open end of said container body so that said flattened hem serves as an anvil to prevent shearing of said cover skirt during the seaming and scoring steps.

4. The method of forming an easy opening container, comprising the steps of positioning a cover in the open end of a container body having an outwardly turned closed curl on the marginal portion thereof adjacent said open end, said cover having a peripheral skirt extending over said marginal portion, engaging said cover skirt with a first seaming roll to press said skirt into contact with said closed curl and said marginal portion to partially seam said cover and said container body together and to flatten only the portion of said closed curl farthest from said open end, and engaging said cover skirt with a second seaming roll and a scoring roll to completely seam said cover and said container body while simultaneously forming a circumferential score line in the outer surface of said cover skirt adjacent to said flattened portion and between the extremities thereof to create a removable tearing strip in said skirt, whereby the unflattened portion of said closed curl adjacent said open end provides a laterally outwardly extending surface over which said cover skirt may be snapped when said cover is used as a reclosure.

5. The method of claim 4 wherein the raw edge of said container body is positioned at the extremity of said flattened portion nearest the open end of said container body so that said flattened portion serves as an anvil during the seaming and scoring steps to prevent shearing of said cover skirt.

References Cited by the Examiner UNITED STATES PATENTS 1,741,918 12/1929 Burbank 22054 2,159,325 5/1939 Fabrice 113-121 2,365,350 12/1944 Marek 113121 2,579,465 12/1951 Birkland 22054 3,005,570 10/1961 Maulaz 22054 3,055,539 9/1962 Pillnik 220--54 3,142,280 7/1964 Heinle 113121 CHARLES W. LANHAM, Primary Examiner.

THERON E. CONDON, Examiner. 

1. THE METHOD OF FORMING AN EASY OPENING CONTAINER, COMPRISING THE STEPS OF POSITIONING A COVER IN THE OPEN END OF A CONTAINER BODY HAVING AN OUTWARDLY TURNED CLOSED CURL ON THE MARGINAL PORTION THEREOF ADJACENT SAID OPEN END, SAID COVER HAVING A PERIPHERAL SKIRT EXTENDING OVER SAID MARGINAL PORTION, PRESSING SAID COVER SKIRT INTO CONTACT WITH SAID CLOSED CURL AND SAID MARGINAL BODY PORTION TO SEAM SAID COVER AND SAID CONTAINER BODY TOGETHER AND TO REFORM INTO A FLATTENED HEM ONLY A POR- 